Laura M Plunkett

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Atrial natriuretic peptides, produced in the mammalian cardiac atrium, are released into the general circulation and may be actively involved in the control of blood pressure and in fluid homeostasis as antagonists of the peripheral angiotensin system. Certain cardiovascular effects of atrial natriuretic peptides may be centrally mediated, as binding sites(More)
Atrial natriuretic factor is a recently-discovered family of biologically active peptides produced in, stored and secreted by mammalian atria. ANF exerts a wide variety of actions in the periphery as well as within the central nervous system. In general, these actions are directed toward the maintenance of body fluid and electrolyte balance and regulation(More)
We report the localization of angiotensin-converting enzyme (kininase II, EC in discrete nuclei and areas of the rat brain by a quantitative autoradiographic technique using image processing coupled to computerized microdensitometry, after incubation of brain sections with the specific converting enzyme inhibitor [125I]351A. High(More)
Somatostatin has been localized in several hypothalamic and extrahypothalamic brain regions where it may function as a classical neurotransmitter or as a modulator of neural activity. In the present study, somatostatin binding sites were studied by incubation of coronal sections of rat forebrain with 125I-Tyr1-somatostatin, Ultrofilm autoradiography,(More)
Binding sites for atrial natriuretic factor (ANF-28) were studied in forebrain areas of spontaneously hypertensive (SHR) and Wistar Kyoto (WKY) normotensive male rats by quantitative autoradiography. The maximum binding capacity of [(125)I]ANF-28 was significantly reduced in the subfornical organ and choroid plexus of 4 and 14 week old SHR rats compared to(More)
Angiotensin II receptors have been quantitated in single rat adrenal medullas by incubation of tissue sections with 125I-[Sar1]-AII, autoradiography with exposure to 3H-sensitive Ultrofilm, computerized densitometry and comparison with 125I-labelled standards. Rat adrenal medulla contains a single class of high affinity AII receptors with a Ka of 0.84 +/-(More)
Cardiovascular and lethal effects of intravenous cocaine infusion were compared in guinea-pigs pretreated chronically with morphine or saline. Alzet minipumps filled with either morphine solution (30 micrograms/kg/hr for 6 days) or isotonic saline were implanted subcutaneously in animals 6 days before cocaine infusion. On the morning of the 7th day, animals(More)
Autoradiographic techniques coupled with computerized microdensitometry and comparison with 125I standards were used to characterize and quantitate receptors for neuropeptides in rat brain and adrenal and pituitary glands. These techniques are rapidly performed, anatomically precise, and more sensitive than membrane binding techniques. They permit the(More)
We describe a quantitative autoradiographic technique which allows measurement of angiotensin-I-converting enzyme [ACE] (kininase II, peptidyldipeptide hydrolase, EC levels in discrete areas of pituitary and adrenal glands in individual animals. Tissue sections were incubated with 125I-351A, a specific ACE inhibitor, and results were obtained with(More)
Angiotensin II binding sites were localized and quantified in individual brain nuclei from single rats by incubation of tissue sections with 1 nM 125I-[Sar1]-angiotensin II, [3H]-Ultrofilm autoradiography, computerized microdensitometry and comparison with 125I-standards. High angiotensin II binding was present in the circumventricular organs (organon(More)